barely any guidebook come pre-drilled, and it's a shame. true, if you play your cards right you can just photocopy the relevant pages, or copy them out the evening before, but sometimes you get to a route and there's three parties on it, or it's wet, or whatever. if you go to the next route on the cliff and want to bring the topo, maybe the book is tagging along, and it sure is nice to be able to clip it in.
i've seen a few folks self-drill guidebooks and make a real mess. if you just chuck up your favorite bit and have at it, the pages will get torn up and bent on the way in.
to drill a hole in your book you'll need two pieces of scrap wood and a clamp. pick your bit (i like 5/16". not so small it catches on small accessory cord, not so big it gets too close to the edges of the book where i drill) and chuck it and drill a hole near the edge of one of your scrap pieces.
then flip through your guide and see where the best spot to drill is. dont put it too close to the edge, or the first time you get your book wet and yank on the clip-in loop, it's going to rip right out. oftentimes, there is just blank space near the top binding and you can drill at leisure. sometimes you clip chapter headings and whatnot, but ive yet to have a guidebook that couldn't be drilled without making anything indecipherable. make a mark on the cover where you want the hole, and sandwhich the book between the two scraps, with the pre-drilled hole over the mark. make sure the bottom scrap does not have a hole where the exit wound will be, so to speak, and make sure the bottom scrap completely covers where the hole will be.
then clamp the sandwhich together very tightly, and drill. you may find that the exit hole is cleaner than the entry hole. if you don't like this, remember to drill the book from back to front.